This study is a randomized, double-blind, three-arm placebo controlled trial designed to evaluate the clinical outcome of trauma patients with severe TBI as manifested by a pre-hospital GCS of 8 or less. Patients will be randomized to a single 250cc IV dose of 7.5% saline in 6% Dextran-70 (HSD), 7.5% saline (HS) or normal saline as the initial fluid for pre-hospital resuscitation. No additional interventions will occur once the patient is admitted to the hospital. In hospital data collection will last up to 28 days. Patients will have neurologic outcome measurements at discharge, 1 month post discharge, and 6 months post injury. Enrollment will be restricted to age ≥ 15 years or ≥ 50 kg if age is unknown.